Robust coherent control in non-Hermitian cavity electromagnonics using counterdiabatic driving

Abstract

We propose to use counterdiabatic driving (CD) shortcut and the Floquet engineering to realize the robust and fast state transfer in the dissipation cavity magnon-polaritons non-Hermitian (NH) system. For the two-level NH cavity magnon-polaritons Hamiltonian, an accurate and fast population transfer is achieved from the microwave photon to the magnon by two coherent control techniques; counterdiabatic driving shortcut and non-Hermitian shortcuts (NHSs). Additionally, by using the CD technique, the population evolution speed of non-Hermitian systems is faster than that via the NHS technique in the broken-symmetric regime. Furthermore, we compare their performances in the presence of the coupling strength and systematic errors, the CD technique features a broad range of high efficiencies of the transition probability above 99.9%, showing that the CD technique is more robustness against these errors than the NHS technique. It is worth noting that this advantage becomes more significant as the gain rate of system parameters increases. The work provides a basis for achieving the robust coherent control in NH cavity electromagnonics.

Figures (8)

• Figure 1: The yttrium iron garnet (YIG) sphere is coupled to a microwave cavity.
• Figure 2: Phase diagram under different conditions of the gain rate $\kappa_{m}$ and the coupling strength $g_{m}$ in units of the cavity decay rate $\kappa_{c}$. There are two borders, the red line shows the border between the $\mathcal{P} \mathcal{T}$-symmetric phase (on the right hand) and the broken-$\mathcal{P} \mathcal{T}$-symmetric phase ( on the left hand). The black dashed curve and black solid line are the border between the asymptotically stable (below the border) phase and the unstable (above the border) phase.
• Figure 3: The figures plot the time evolution of the relative populations as a function of time with parameters $\omega_{c}/\omega_{d}=85,$$\omega_{m}/\omega_{d}=35$ and $\varepsilon_{m}/\omega_{d}=50$, $P^{r}_{0}$ and $P^{r}_{1}$ are the relative populations of the microwave photons and the magnons, respectively. (a) $g_{m} /\omega_{d}=0.1$, (b) $g_{m} /\omega_{d}=0.3$, (c) $g_{m} /\omega_{d}=0.6$, (d) $g_{m} /\omega_{d}=1$.
• Figure 4: The figures plot the time evolution of the relative populations as a function of time with parameters $\omega_{c}/\omega_{d}=85,$$\omega_{m}/\omega_{d}=35$ , $\varepsilon_{m}/\omega_{d}=50$, $g_{m}=1$ and $P^{r}_{0}$ and $P^{r}_{1}$ are the relative populations of the microwave photons and the magnons, respectively. (a) $\kappa _{c}=1,\kappa _{m}=0.3$, (b) $\kappa _{c}=1,\kappa _{m}=0.6$, (c) $\kappa _{c}=1,\kappa _{m}=1$, (d) $\kappa _{c}=2, \kappa _{m}=2$.
• Figure 5: Transition probabilities versus coupling strength error $\alpha$ (dimensionless parameter). In the NHS (black, dashed line), the parameters are $\omega_{c}/\omega_{d}=85,$$\omega_{m}/\omega_{d}=35$ , $\varepsilon_{m}/\omega_{d}=50$, $g_{m}=1$. In the CD (red, solid line), (a) $g_{m}>\left ( \kappa _{c}+ \kappa _{m} \right ) / {2}$, $\kappa _{c}=1$, $\kappa _{m} =0.3$, (b) $g_{m}=\left ( \kappa _{c}+ \kappa _{m} \right ) / {2}$, $\kappa _{c}=1$, $\kappa _{m} =1$, (c) $g_{m}<\left ( \kappa _{c}+ \kappa _{m} \right ) / {2}$, $\kappa _{c}=2$, $\kappa _{m} =2$. All parameters are the same as those in Figs. \ref{['fig1']} and \ref{['fig2']}, respectively